During knee arthroplasty, particularly a partial knee replacement, the joint is prepared by first resecting the tibial plateau. Following resection of the tibial plateau, one or more holes are then drilled into the femoral condyle to receive a cutting guide for resecting the condyle. Conventionally, a hole is made in the intramedullary canal of the femur, into which an intramedullary rod is inserted. The intramedullary rod acts as a reference for the drilling of the hole or holes which locate the cutting guide. These holes may also serve to locate the femoral component of the prosthetic following resection of the femoral condyle.
The femoral component may comprise a single fixation peg or two fixation pegs which are received in holes in the femur. In addition or as an alternative, the femoral component may comprise one or more webs. The webs may be thin layers of material, which may extend between the pegs.
A two peg component provides greater coverage (i.e. a larger degree of rotation) and may be selected where the patient's lifestyle is such that they are squatting regularly.
As described previously, the intramedullary rod is used as a reference for locating the hole(s) for receiving the cutting guide. A drill guide may be used to reference from the intramedullary rod in order to properly locate the cutting guide. Existing drill guides require the surgeon to align the drill guide with the intramedullary rod in various planes so that the guide hole is placed in the correct position on the femur.
In a known technique, a tibial template is placed on the resected tibial plateau and the drill guide inserted into the operative wound. A feeler gauge is then inserted in between the tibial template and the drill guide. Due to this layering of components there is a stack up in the tolerances of each component.
It is desirable to provide a drill guide which has a simplified alignment process.